Naturally occurring polypeptides or proteins often fold into complex, three-dimensional shapes that determine both chemical and physiological functionality. Thus a thorough understanding of proteins necessarily involves a detailed representation of their spatial topography. The field of protein crystallography has flourished over the last 20 years resulting in a rapid increase in the knowledge bas of protein structure enabling great strides in other disciplines including biochemistry, pharmaceutical development and cell biology. However, the structural biology field has largely been restrained to working with protein that is naturally soluble in aqueous media, or made soluble by incorporation into surfactant micelles. The present invention provides methods and compositions that allow for the study of membrane-embedded proteins (i.e., integral membrane proteins) in a more natural membrane bilayer environment. The present invention enable a more detailed analysis of important classes of membrane-embedded polypeptides that play key roles in a variety of cellular processes including energy and signal transduction.